Knitting processes and knitting machines



May 22, 1962 K. G. MACQUEEN 3,035,426

KNITTING PROCESSES AND KNITTING MACHINES Filed Aug. 19, 1957 6 Sheets-Sheet 1 lLUlUIJJlUJlUlULUllU UHTTUUTTIIIIIIIIIHUTF lNVE NTOR xfennef/l G. Macqueen A'r-roreNEY-i May 22, 1962 K. G. MACQUEEN KNITTING PROCESSES AND KNITTING MACHINES 6 Sheets-Sheet 2 Filed Aug. 19, 1957 FIG. 2.

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KNITTING PROCESSES AND KNTITIIHK; MACHINES Filed Aug. 19, 1957 6 Sheets-Sheet 5 INVENTOR ATTORNEYS May 22, 1962 K. G. MACQUEEN 3,035,426

KNITTING PROCESSES AND KNITTING MACHINES Filed Aug. 19, 1957 6 Sheets-Sheet 6 AT TOR NEY United States This invention relates to knitting processes and machines and has for its object to enable garments or other articles of apparel of a wide variety of shapes and sizes to be knitted expeditiously and more economically than is possible with existing methods or machines.

At the present time, knitted garments are made either by first knitting flat sections which are fashioned at the side edges to provide a predetermined shape when the separate sections are seamed or linked together, or by knitting fabric which is cut to a pattern or measurements and then tailored to a required shape.

According to the present invention, a method of knitting a garment comprises knitting courses by forming stitches on all the needles of a flat bed knitting machine within the overall knitting width, and knitting on selected and variable numbers of said needles and holding on the remainder of said needles course by course, as determined by control means responsive to electrical impulses produced by scanning means as it scans a pattern element consisting of a recording medium on which is recorded a required knitting information, thereby to form a complete three-dimensional garment of a shape determined by said knitting information.

According to a further feature of the invention a knitting machine for carrying into effect the method of knitting according to the invention comprises a flat needle bed, needles slidably supported on said bed, a cam box movable along said needle bed for engaging the needles to elfect knitting operation thereof meansfor'variabledetermining for each knitting course the extent of traverse of the cam box along the needle bed, selecting means for rendering individual needles and groups of needles inoperative for the knitting of each course and means responsive to electrical impulses produced by scanning means as it scans a pattern element consisting of a recording medium on which is recorded a required knitting information for controlling the operation of said traversedetermining and needle-selecting means.

Conveniently, the means for controlling the operation of the knitting machine is electrically operated and the recording medium comprises a perforated tape or tapes which are scanned by means of photo-electric cells upon which light passing through the perforations of the tape is caused to impinge. Two tape records may be provided one of which-hereinafter referred to as the operational control tapecontrols the various operations of the machine while the otherhereinafter referred to as the needle pattern control tapecontrols the operation of the individual needles of the machine to give a desired knitting pattern. There may be two or more needle pattern control tapes to enable the pattern of knitting to be varied during the knitting of a garment, the change-over from one knitting pattern to another being eflfected under the control of the operation control tape.

In one form of control means for controlling the operation of a knitting machine according to the invention there is provided an operational control scanner which scans the operational control tape which is provided with two rows of perforations for each knitting course. The perforations of one row are scanned by the operational control scanner and according to the positioning of the perforations the potentiometer of a digital to analogue potentiometer comparator is preset to a given resistance ice which determines the length of travel of the cam box of r the knitting machine thereby determining the length of each knitting course. The other row of perforations scanned by the operational control scanner is employed to operate a number of decoding units which may, for example, control the racking of the knitting beds in the case of a double-bed machine, the selection of knit-ting yarn, the adjustment of the stitch length, and the speed of travel of the cam box, i.e. the knitting speed.

The control apparatus also includes one or more needle pattern serial scanners which scan the needle pattern tape or tapes and control the operation of means on the cam box for sequentially operating the needle jacks to one of two positions, i.e. knitting or non-knitting, as the cam box traverses the needle bed.

The traverse of the cam box along the bed of the machine is preferably effected by means of an endless chain driven by an electric motor and a servo link connects the chain drive motor with the drive motor of the needle pattern serial scanner thereby to ensure exact synchronism of the speed of movement of the cam box and the speed of scanning of the needle pattern tape.

The knitting method and machine according to the invention is especially applicable to the mass production of knitted garments and the control means may be designed -as'a separate unit to which a number of slave knitting machines can be connected by suitable plug and socket connections. Thus, there may be a number of control units each provided with an operational control tape corresponding to a distinct form of garment and the number of knitting machines connected to each control unit can be varied depending upon the demand for a particular form of garment.

The invention will now be described with reference to the accompanying drawings, in which:

FIGURE 1 is a general schematic diagram of a double bed knitting machine and control means therefor for carrying out the knitting method according to the invention;

FIGURE 2. is a schematic diagram illustrating the method of operating a plurality of slave knitting machines from a master control;

FIGURES 3(A) and 3(B) together give a detailed circuit diagram of one form of the control means shown in FIGURE 1 and applied to a single bed machine;

FIGURE 4 is a detail showing one form of tape scanner for use in the needle pattern scanning means of FIG- URE 3;

FIGURES 5 and 6 respectively are details showing an alternative form of tape scanner for use in the needle pattern scanning means of FIGURE 3;

FIGURE 7 is a transverse section through one bed and the corresponding cam box of the knitting machine of FIGURE 1, the section being taken along the line VIIVII of FIGURE 8;

FIGURE 8 is an underneath plan view of the cam box of FIGURE 7;

FIGURE 9 is an elevation of a needle of the machine drawn to an enlarged scale;

FIGURE 10 is a longitudinal section of a clutch unit of the cam box of FIGURES 7 and 8;

FIGURE 11 is a section taken along the line XIXI of FIGURE 10, and

FIGURE 12 is a diagram showing how the courses are knitted for forming a garment by the method according to the invention.

Referring to FIGURE 1 of the drawings there is shown diagrammatically at 1 a double fiat bed knitting machine having two needle beds 2 and 3 respectively and a double cam box 4 connected to an endless drive chain 5 driven by a motor 6. The operation of the chain driving motor 6 is controlled by a comparator 7 having a potentiometer the resistance of which is preset by a decoding unit 8 operated from an operational control scanner 9 according to perforations carried on an operational control tape (not shown). A variable resistor 10, the resistance of which is varied according to the distance moved by the cam box, is connected to the comparator 7 the arrangement being such that when the resistance of the variable resistor 10 is equal to the preset resistance of the potentiometer of the comparator the input to the drive motor 6 is interrupted and the cam box therefore is brought to rest at a position along the needle bed depending on the presetting of the potentiometer of the comparator. The aforementioned operational control tape is provided with a further row of perforations for each knitting course and these are divided into four sets, the sets being scanned by the operational control scanner for controlling the operation respectively of a miscellaneous operation unit 11, a yarn selection decoding unit 12, a stitch length control decoding unit 13 and a cam box speed decoding unit 14.

The miscellaneous operation unit 11 is connected to means (not shown) for controlling miscellaneous operations of the machine such as, for example, racking of the needle beds. The yarn selection decoding unit 12 is connected through a multi-wire cable 15 to eight yarn selecting solenoids 16 on the cam box for selecting the appropriate yarn or yarns to be knitted. The stitch length control decoding unit 13 controls the operation of motors 17 on each section of the cam box for varying the position of the needle-operating cam transversely of the needle beds thereby to vary the length of stitch and finally the cam box speed decoding unit 14 controls the speed of the chain drive motor 6 according to the indications given on the operational control tape.

There is also provided a pair of needle pattern serial scanners 18 each driven by an electric motor 19 and which scan a needle pattern tape (not shown) and by means of a photo-electric scanning device indicated diagrammatically at 20 pass impulses through a distributor 21 and amplifier 22 to clutch units 23 positioned on each section of the cam box. The clutch units 23 each comprises three magnetically operated clutches for selectively engaging any one of three striker discs (109 FIG. 10) with a continuously rotating shaft 112 driven by a motor 24. The striker discs are provided with strikers adapted to engage the butts of the jacks when the corresponding clutch is engaged and in this manner the jacks are moved to one of three positions according to which magnetic clutch is operated. As will be seen from the drawing there is provided on each section of the cam box a clutch unit 23 at each end thereof and for use when the cam box is moving in one direction or the other.

FIGURE 2 shows how a number of slave knitting machines can be connected to a master control unit by means of multi-wire cables and plug-in connections so that the number of knitting machines connected to a given master control uni-t can be varied at will. As will be seen from the FIGURE, the master control unit 25 includes an operational control scanner 9 and one or more needle pattern serial scanners 18, as described with reference to FIGURE 1, and also a re-transmission unit 26 having a plurality of connections leading to outlets or connecting sockets 27. A number of knitting machines 28, each with its associated slave control feeder unit 29, multi-wire cable 30 and multi-contact plug 31 can be connected as desired to the master control unit 25 by inserting the plug 31 in the appropriate socket 27. It will be appreciated therefore that the arrangement of FIGURE 2 leads to great flexibility in knitting production since the number of machines engaged on knitting one type of garment can be varied and machines can be switched to knitting another type of garment merely by removing the plugs from one master control unit and inserting them in another unit corresponding to the said other type of garment. Furthermore, the master control unit may be provided with a number of pattern serial scanners having different pattern tapes and the connecting plugs and sockets may be arranged so that while all the machines connected to the same master control unit are connected to the same operational control leader so as to produce garments of identical size and shape, each slave machine or group of slave machines can be connected to a different needle pattern scanner so that the knitting pattern of the garments is varied between one machine or group of machines and another.

Referring now to FIGURES 3(A) and 3(B) there is shown in detail one circuit arrangement suitable for carrying the invention into effect and in which similar reference numerals to those of FIGURE 1 are employed where applicable. The lines connecting the various units in FIGURES 3(A) and 3(B) and representing the electrical connections therebetween are intended to be diagrammatic and in most cases a single line represents a plurality of connecting wires extending between two units.

The two tape serial scanners 18 are driven from a common driving shaft 32 driven from a drive control unit 33, the shaft 32 in each scanner being connected through gearing 34, to sprocket wheels 35 which in known manner engage in a perforated needle pattern tape (not shown) for advancing the tape beneath a scanning means indicated generally at 36 which scans the perforations of the tape and, in accordance therewith, transmits to the clutch units 23 of the cam box impulses which cause the clutch units to operate the needle jacks in accordance with the pattern recorded on the pattern tape. Alternative forms of scanning means 36 will hereinafter be described with reference to FIGURES 4, 5 and 6. Also driven from the common drive shaft 32 and in synchronism with the tapes is a distributor 37 comprising a rotating arm 38 moving over three equal arcuate segments 39 each of which is connected through a changeover contact W2 of a control switch 77 to a corresponding clutch of the clutch units 23. The control switch operates, as will hereinafter be described to connect the segments 39 alternately to the clutch unit at one or the other end of the cam box according to the direction in which the cam box moves. Also included in the drive from the shaft 32 to the tape advancing sprockets 35 is a pattern pitch advance mechanism 40 which comprises a single revolution shaft 41 operated by a relay L in the case of one serial scanner or by a relay R in the case of the other serial scanner. The single revolution shaft 41 is geared to a differential gear unit 42 included in the drive from the shaft 32 to the sprocket 35 and the gearing is so arranged that a single revolution of the shaft 41 causes the tape to be advanced exactly one pattern pitch, the relay L or Ras the case may be-being energised to cause the shaft 41 to make one revolution under the control of the operational control scanner as will hereinafter be described. The relays L and R at their contacts L1, R1 also serve to operate a differential relay V having a change-over contact 43 which according to whether contact L1 or contact R1 is closed switches the output from one or other of the scanning means 36 to an amplifier 44 connected to the arm 38 of the distributor 37.

The drive unit 33 includes a servo motor 45 drivingly connected to the drive shaft 32, a servo amplifier 46, a field control unit 45a, and a mag-slip receiver 4'7. The field control unit 45a and the mag-slip receiver 47 are connected respectively to a generator 48a and a mag-slip transmitter 48 driven by the cam box drive motor 6 so that the motor 45 rotates in synchronism with the cam box drive motor 6.

The operational control scanner 9 comprises a motor 49 for driving the operational control tape (not shown) which is provided with two lines of perforations for each knitting course, the two lines being scanned at the same time. The first line of each knitting course is scanned by thirteen stationary photo-transistors 50 and controls the number of stitches in the course to be knitted, i.e. it controls the distance to be travelled by the cam box in one direction or the other from the starting needle to a selected finishing needle which in turn is the starting needle for the next course. The second line of perforations is scanned by sixteen stationary photo-transistors 51 which are divided into four groups of four as will hereinafter be more fully described, and the output from each group of four is fed through a multi-channel amplifier 52 to the decoding units 11, 12, 13 and 14.

The miscellaneous operation relay unit 11 comprises four relays 53 which are operated in accordance with the outputs of the first group of four transistors 51. The contacts of the relays 53 are connected in known manner to form a relay tree by which any one of sixteen outgoing circuits 54 can be connected to single input 55. The output circuits 54 are each connected to suitable means for eifecting miscellaneous operations of the knitting machine such as racking, needle transferring and, for example, one of the output circuits 54a is connected to a relay 56 for effecting at its contacts 56a the change-over from one needle pattern serial scanner to the other.

The yarn selector relay unit 12 also comprises four relays 57 operated in accordance with the outputs of the second group of photo-transistors 51, the contacts of the relays 57 being interconnected to form a relay tree providing eight output circuits 58 and a single input 59. Each of the output circuits 58 is connected through a cable 60 to a separate one of the yarn selector solenoids 16 so that the appropriate yarn selector solenoid or solenoids is or are operated to select a given yarn or combination of yarns according to the appropriate perforations of the operational control tape.

The stitch length control relay unit 13 comprises four relays 61 operated in accordance with the outputs of the third group of four photo-transistors 51 and the contacts of which are arranged to control the effective resistance of two limbs 62 and 63 respectively of a bridge circuit, the other two limbs of which are constituted by a potentiometer 64 having a rotating contact arm 65 driven in synchronism by the stitch length control motor 17. Thus, depending upon the actuation of the relays 61 the bridge circuit may be unbalanced and causes an EMF. to be applied across the stitch control motor 17 which then rotates to adjust the length of stitch as will hereinafter be described, until the arm 65 of the potentiometer moves to a position in which the bridge is again balanced and the E.M.F. across the motor 17 reduced to zero.

Signals from the pattern tape scanning means indicate whether a stitch is to be knitted or tucked and the length of stitch varies accordingly. In order to feed the required length of yarn to give a uniform fabric a means (not shown) is provided for measuring the yarn fed to the needles and comparing the measured length with the required length as indicated by the needle pattern scanner. The said means may comprise a potentiometer having a sliding contact which is driven by the yarn as it is fed to the needles so that the setting of the potentiometer is proportional to the length of yarn per stitch. The potentiometer resistance is compared with a resistance which is preset under the control of the pattern serial scanner to a value proportional to the required length of stitch and the result of the comparison determines the operation of the stitch length control motor 17 which adjusts the needle-operating cam in one direction or the other until the required length of stitch is produced. In order to provide for a constant yarn tension, there may be employed a constant torque motor (not shown) which feeds the yarn off from the cone, bobbin or pirn so that a constant tension of a predetermined value is maintained between the cone, bobbin or pirn and the needles.

The cam box speed control relay unit 14 comprises four relays 66 each of which is provided with a normally open make and break contact 67. The contacts 67 are respectively connected across resistors 68 connected in the input circuit of an amplifier 6h feeding the cam box drive motor 6. The four resistors 68 are connected in series and are each of a different resistance value and it will thus be apparent that by operation of suitable combinations of the relays 66 there can be obtained sixteen different resistance values of the combined resistors 63 thereby to give sixteen different speeds of the cam box motor 6.

Referring now to the comparator 7 of FIGURE 1, this is shown in FIGURE 3 as comprising a digital to analogue potentiometer comparator having a potentiometer comprising a number of resistor units 70 connected to form a series parallel arrangement and each adapted to be short-circuited by a contact of a plurality of relays 71 so that upon operation of selected ones of the relays the effective resistance of the series parallel arrangement is varied. There are thirteen relays 71 each connected to one of the photo-electric transistors Si by means of a multi-channel amplifier '72 so that the relays are operated or not operated according to the perforations of the operation control tape. The relays 71 are divided into three groups of four relays and one group of one relay. Each relay 71 is provided with a pair of normally open contacts and a pair of normally closed contacts which are respectively connected across corresponding resistors 7t) in the two arms of the series parallel arrangement so that when a given relay 71 is released the corresponding resistor 7t! in one arm is short-circuited and the corresponding resistor in the other arm is open circuited and by suitably proportioning the values of the several resistors 76 it is possible to vary the effective resistance of the arms of the series parallel arrangement in steps of 1 ohm. Thus, for example, the first group or" four relays 71 controls four resistors having resistances of 1, 2, 3 and 4 ohms respectively; the second group of four relays 71 controls resistors having resistances of 10, 26, 30 and 40 ohms respectively; the third group of relays 71 controls resistors having resistances of 100, 200, 300 and 400 ohms respectively; and the relay 71 of the last group controls resistors having resistances of 1,000 ohms. As stated the relays 71 are operated in accordance with the perforations of the operation control tape and as an example the relays thus operated may be relays 2 and 4 of the first group, relays 3 and 4 of the second group, relay 2 of the third group and the relay of the fourth group the effective resistance thus being 1,276 ohms.

The arrangement of resistors 70 is connected to a potentiometer 73 having a contact arm 74 which is rotated in synchronism with the cam box drive, the resistors 70 and the potentiometer 73 thus constituting a bridge circuit connected across the cam box drive motor 6 so that when the bridge is unbalanced and is applied to the motor which thereby drives the cam box and the potentiometer arm 74- until the bridge is balanced. The

setting of the resistors 70 thus determines the extent of travel of the cam box and by suitably selecting the speed of the drive motor and the driving connection thereof to the cam box it can be arranged that each ohm resistance of the resistors 75? corresponds to the movement of the cam box from one needle to the next, so that in the above mentioned example in which the resistors 7 i) are set to give a resistance of 1,276 ohms the cam box would be advanced to needle 1276.

However, it is required that upon return movement of the cam box the knitting should start at needle 1276 and it is therefore necessary to provide. for additional movement of the cam box corresponding to the distance between the two clutch units 23 which will be referred to as the distance x. This additional travel is automatically provided for in the comparator by means of a relay X/l which inserts an additional resistance 75 in the bridge circuit to give the required additional travel. of the cam box so that upon the return movement the appropriate clutch unit 23 commences operation at needle 1276.

Upon completion of knitting of a course and while the cam box is advancing the additional distance x, it is necessary to cause the pattern pitch advance mechanism of the appropriate needle pattern scanner to operate in order to advance the pattern tape one pitch. This is effected by means of a relay D connected to a discriminator circuit 76 which compares the instantaneous out-of balance voltage of the input to the cam box drive motor amplifier 69 with a set voltage so that when the compared voltages are equal the relay D operates and at D1 closes a contact to energise the pattern pitch advance mechanism 40 of the corresponding needle pattern serial scanner and at contact D2 applies earth to the input to the amplifier 44 thereby to render ineffective the output from the scanning means 36 of the appropriate needle pattern serial scanner. The operation of contact D2 also closes a circuit for relay X/ 1 which operates and at its contact Z1 closes a holding circuit over the contact D2.

It will be understood that means other than the digital analogue comparator arrangement shown and described for example, bi-directional Dekatron counters may be employed for determining the length of traverse of the cam box.

Should the operation of the pattern pitch advance mechanism take longer than the time taken by the cam box to advance the additional distance x there is provided a security sequence device which prevents the starting of the cam box on a fresh course of knitting until the full advance of the pattern tape and all other simultaneous actions required have been effected. The security sequence device comprises a relay M/1 the energising circuit of which is connected through normally open contacts S1, S2, S3, S4, and S5 of relays S1, S2, S3, S4, and S5 connected respectively in the common return circuit of the relays 71 of the comparator 7, the relays 66 of the cam box speed control unit 14, the relays 61 of the stitch length control relay unit 13, the relays 57 of the yarn selector unit 12 and the relays 53 of the miscellaneous operation unit 11. The relay M/l at its normally made contact M1 applies earth to the input to the cam box drive motor amplifier 69 to prevent the motor from operating and only when all the relays S1, S2, S3, S4 and S5 are operated the relay M/l operates to remove earth from the amplifier 69 thereby to permit the cam box drive motor to operate.

In order to effect the necessary change-over of selected circuits at the end of each travel of the cam box the control switch 77 comprises a relay W/4 connected to a voltage generator 78 on the shaft of the cam box drive motor, the arrangement being such that the relay W/4 operates only when the generator voltage is zero, i.e. the cam box has arrived at the end of its travel. The relay W/ 4 upon operating closes its contact W1 to cause the operational control scanner drive motor 49 to operate and advance the operational control tape. At its contacts W2 the relay W4 switches the segments 39 of the distributor 37 from one clutch unit 23 to the other, at its contact W3 opens the circuit of relay Z/l which restores and at Z1 removes the earth from the input to the amplifier 44 to permit the output from the appropriate needle pattern scanner to again become effective and at its contact W4 causes the relay X/ 1 of the comparator 7 to operate to insert the resistor 75 in the appropriate arm of the bridge circuit depending upon the direction of travel of the cam box.

In FIGURE 4 there is shown one form of the scanning means 36 of the needle pattern serial scanner. In the arrangement shown in FIGURE 4 the pattern tape 79 is passed over a curved roller 80 to cause the tape to assume an arcuate forrn transversely of the tape concentric with the drive shaft 32. The arcuate tape is fed over a member 81 of a translucent material such as, for example, perspex sheet, having a curved upper surface 82 matching the curvature of the tape and having an edge lighting lamp 83 disposed beneath the lower surface thereof. The member 81 is of a thickness equal to the line pitch of the tape so that as the tape is advanced each line of perforations 84 will be illuminated from underneath.

Secured upon the end of the shaft 32 is a scanning device consisting of four radially extending members 86 each supporting on its outer end a photoelectric cell 87. The members 86 are disposed in a plane coinciding with the plane of the member 81 and the output from the photoelectric cell is connected to slip rings 88 which are engaged by brushes 89 having leads 90 connected thereto.

Thus, as the shaft 32 is rotated the photo-electric cells 87 scan sequentially the perforations 84 and according to the light impulses received transmit corresponding electric pulses to the input to the amplifier 44.

In the alternative form of scanning means shown in FIGURES 5 and 6 the pattern tape 79 is fed over a row of photo-electric cells 91 corresponding in number to the maximum number of perforations that can occur in one line. Disposed above the pattern tape is a masking member 92 which extends transversely across the tape and is provided with a row of spaced apertures 93 coinciding with the photo cells 91. Disposed above the masking member 92 is a scanning member 94 which comprises a glass cylinder 95 (FIGURE 6) extending transversely of the tape above the row of apertures 93 and adapted to be driven from the drive shaft 32. As shown in FIG- URE 6 the glass cylinder 95 is masked by means of an opaque coating 96 to provide two unmasked slots 97 of helical form and each extending through 180 from one end of the cylinder to the other. The combination of the two unmasked slots 97 results in the formation of a diamond-shaped transparency extending vertically through the cylinder and which-as the cylinder is rotated-moves lengthwise thereof so that by means of a tubular lamp 98 positioned above the cylinder 95 light is transmitted through the diamond-shaped transparency to each of the apertures 93 in turn and if a perforation on the tape coincides with an aperture 93 the corresponding photoelectric cell 91 is energised to give a required output.

FIGURE 7 shows a transverse section through one bed and the corresponding cam box of the knitting machine in which the bed 2 is provided with a plurality of transversely extending slots 99 each adapted to accommodate a jack 100 and knitting needle 101. The cam box supports on the underface thereof a pair of needle-operating cams 102, a needle positioning earn 102:: and jack-operating cams 103 adapted to engage respectively in known manner the butts of the needles and jacks. A cam track 1021) is provided for operating the bolts of the tubular bolt needles hereinafter described with reference to FIG- URE 9 when these are provided. Each needle-operating cam 102 is slidable transversely with respect to the cam box in order to vary the length of stitch and the said transverse sliding movement is effected by means of a pin 104 eccentrically mounted on the end of a vertical shaft 105 and sliding in a rectangular slot 106 in the cam 102 so that upon rotation of the shaft 105 in one direction or the other the cam is caused to move transversely by the cam box and forwardly or rearwardly with repsect to the front edge of the needle bed 2. The shaft 105 is driven through gearing 105a by the motor 17 and the arm 65 of the potentiometer 64 is secured to the upper end of the shaft 105 so that the potentiometer arm is driven in synchronism with the movement of the needle cam 102 as hereinbefore described.

The needles 101 are individually slidable in the appropriate slots or tracks and are preferably formed of fine tubular steel. As shown in FIGURE 9 each needle comprises a shank 101a formed of fine gauge tubular stainless steel having at one end a knitting hook 101b and at the other end a butt 101a. Slidingly positioned in the bore of the shank is a bolt 101d which may be either tubular or solid and at one end 101e is shaped to engage the point of the hook 101b and at its other end is formed as a butt 101 As the cam box traverses the needle bed the selected needle butts 101a are engaged successively by the needlepositioning cam 102a to position the needles for subse- 9 quent actuation by the needle cam 102, the butts 101 of the bolts being engaged in and actuated by the bolt operating cam track 1021:.

The cam box supports adjacent each end thereof the aforementioned clutch units 23 each of which comprises three electromagnet clutches 108 driven from the motor 24 through a common drive shaft and each adapted when energised and as the cam box moves along the bed, to actuate a striker 107 so that according to the operation of the clutches the strikers are caused to move the jacks into knitting or holding position. As will be more clearly seen in FIGURES l and 11, the striker 107 is supported at the periphery of a disc 109 mounted upon a freely rotatable shaft 110 capable of longitudinal movement and spring biased by means of springs 111. A shaft 112 continuously rotated by the motor 24 through the common drive shaft and appropriate gearing supports at one end adjacent the disc 109 an electromagnet 113 having a coil 114 to which current is fed through brushes 115, and slip rings 116. Thus upon energisation of the coil 114, the disc 109 is attractedtowards the electromagent 113 and is caused to rotate in the direction of the arrow 117 to move the striker into the path of the corresponding jack butt. The movement of the disc 109 is limited by stops 118 and upon deenergisation of the electromagnet 113 the disc is restored to its normal position by a restoring spring 119.

The jacks 100 are divided into groups of three, the jacks of each group being of different length in order to be actuated by one of the three strikers 107 at one end of the cam box. As the cam box slides along the bed, and a knitting signal is received from the'knitting pattern scanner, the striker 107 on the corresponding clutch unit is moved to the operative position and strikes the lower butt 100a of the corresponding jack which is thereby moved forwardly in its track-s0 that the higher butt 100!) of the jack is engaged in the cam track 103 which causes the jack to move further towards the center of the bed and push the associated needle forwardly from its holding position to the knitting position on which the butt 1010 of the needle engages in the cam track 102, while the butt 101 of the needle is engaged in the cam track 102b. In this manner and by reason of the needle butts 101s and 101 in the tracks 102 and 1021) respectively, as the cam box moves along the bed the bolt 101e is caused to open and close on the hook 10111 of the needle to effect the required knitting action.

If no knitting signal is received as mentioned above, i.e. the needle is to hold a stitch, the clutch unit is not energised, the butt is not moved forwardly and the butt 101s of the needle engages in the lower portion of track 102 and butt 1013 again engages in track 1021) so that the needle bolt is not operated and no knitting operation of the needle is effected.

In FIGURE 12 there is shown a portion of a pattern for knitting a ladies dress by the method according to the invention. The pattern indicates how the knitting is effected course-by-course and the numbering of the needles is indicated at the bottom of the figure.

The knitting commences with a number of waste courses 124 of throw-away yarn knitted on all the needles. Knitting on needles 73 to 336 is then held while knitting is continued on needles 0 to 72 to form a pleat 125 at the bottom of the skirt. At 126' knitting is resumed on needels 0 to 300, the subsequent courses being increased in length as at 127 to give the full knitting width which continues to a waist fashioning course 128 in which knitting is held on needles 200 to 336, the courses then successively diminishing to provide for the waist fashioning after which the courses are again extended to the full knitting width as at 129 and then again successively decrease as at 130 to provide the back sleeve fashionin' while at 131 knitting on needles 0 to 196 is held so that the course begins at 132 and subsequent courses are made successively shorter to provide for the under-arm waist fashioning. Knitting is again resumed on needles 0 to 270 and the courses are successively reduced in length as at 134 which provides for the waist-hip fashioning and then courses 135 of linking waste are knitted on needles 0 to 27 0. The garment sleeve commences by knitting on needles 260 to 2'70 and the courses successively increase and then decrease to form a shaped portion 136 which forms half of the sleeve of the garment. Although the pattern for the entire garment is not shown in FIGURE 12, it will be understood that the knitting is cotninued to provide a further sleeve portion followed by linking waste courses and by a waist and bust fashioning portion and so on and at the end of the knitting, further waste courses are knitted followed by another similar garment so that in this manner the garments can be knitted in a continuous fashion and subsequently separated by cutting the intervening waste courses. The linking waste courses such as 135of each garment are then severed and the respective portions of the garment are linked together to produce the finished garment.

It will. be understood that the above described apparatus for carrying out the method according to the invention may be modified to suit particular requirements.

It will be further understood that the invention is not limited to knitting courses which run lengthwise of the garment, but is also applicable to garments in which the knitting courses extend across the width of the garment.

I claim:

1. A knitting machine comprising a flat needle bed, needles slidably supported :on said bed for movement from a holding position to a position for knitting operation, jacks for effecting said movement of the needles, a 'cam box movable along the needle bed, cams on said cam box for effecting knitting operation of said needles when in the knitting position, drive means for traversing the cam box along the needle bed, means controlling operation of said drive means for variably determining for each knitting course the extent of traverse of the cam box along the needle bed, means carried by said cam box and movable from an inoperative position to an operative position for engaging the jacks to effect said operation of the jacks to move the associated needles into position for knitting, electrically operable means responsive to electrical impulses for effecting movement of the said jack engaging means to the jack-engaging position, and a needle pattern serial scanner for producing said electrical impulses by scanning a pattern element, whereby as the cam box traverses the needle bed the needles are moved to the position for knitting or permitted to remain in the holding position in accordance with the impulses produced by said scanner as it scans said pattern element.

2. A knitting machine as claimed in claim 1 in which said electrically operable means comprises a pair of clutch units mounted on the cam box, one for each direction of movement thereof along the needle bed, each said clutch unit comprising a continuously rotated driving member, a driven member movable from a retracted position to an operative jack-engaging position, and electromagnetic means responsive to a said electrical impulse for coupling the said driving and driven members whereby the driven member is moved from retracted to operative position to effect said operation of a jack engaged thereby.

3. A knitting machine comprising a flat needle bed, needles slidably supported on said bed, jacks slidably supported on said bed for moving the needles from a holding position to :a knitting position, a cam box movable along the needle bed, cams on said cam box for effecting knitting operation of the needles when in the knitting position, an electric motor drivingly connected with said cam box for traversing the cam box along the needle bed, a variable first electrical resistance operatively connected with the cam box and variable in response to traversing movement of the cam box to a resistance value proportional to the extent of traverse of the cam box, a second variable electric resistance pre-set-table to a resistance value corresponding to a required extent of traverse of the cam box, a comparator for comparing the first and second electrical resistances and for causing stopping of the drive of the cam box by the motor when the extent of traverse of the cam box reaches the said required extent, an operational control scanner which produces electrical impulses by scanning a first pattern element means responsive to said electrical impulses for presetting said second resistance, means carried by said cam box and movable from a retracted position to an operative position for engaging the jacks to etfect said operation thereof to move the needles into knitting position, a needle pattern serial scanner which produces electrical impulses by scanning a second pattern element and electrically operable means responsive to the electrical impulses produced by said needle pattern serial scanner for effecting movement of said jack-engaging means to the operative position whereby the needles are moved to the knitting position or are permitted to remain in the holding position in accordance with the impulses produced by said needle pattern serial scanner.

4. A knitting machine as claimed in claim 1 in which said means controlling the operation of said drive means comprises an operational control scanner which produces electrical impulses as it scans a cooperating pattern element, and electrically adjustable means responsive to the electrical impulses produced by said control scanner.

5. A knitting machine as claimed in claim 3, including a second drive motor for driving said needle pattern serial scanner, and means synchronising the operation of the said cam box drive motor and said second drive motor, whereby the traversing movement of the cam box is synchronised with the scanning of the second pattern element by the needle pattern serial scanner.

6. A knitting machine as claimed in claim 1 for use with a pattern element of the type consisting of a perforated tape, in which said scanning means comprises photo electric cells supported upon arms and extending radially outward from a drive shaft, means for transversely curving the perforated tape so that the tape is concentric with the drive shaft, and means for illuminating the apertures of the tape line by line to be scanned by the rotating photo electric cells.

7. A knitting machine as claimed in claim 1, for use with a pattern element of the type consisting of a perforated tape, in which the said scanning means comprises a cylinder of translucent material extending transversely across the perforated tape and masked to provide a pair of helical translucent slots disposed so that a diamondshaped transparency extends diametrically through the cylinder and moves lengthwise thereof as the cylinder is rotated, a masking member interposed between the cylinder and the tape on one side thereof, a plurality of spaced apertures extending lengthwise of said masking member, a row of photo electric cells disposed on the other side of the tape and registered with said spaced apertures, and lighting means cooperating with the cylinder to produce a light beam which as the cylinder is rotated traverses the said diamond-shaped transparency and suecessively scans each aperture in the masking member and energises the corresponding photo electric cell when a perforation in the tape coincides with the aperture.

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